Mechanisms and consequences of acquired brain injury during development

Pediatric severe traumatic brain injury mortality prediction determined with machine learning-based modeling

INTRODUCTION

Severe traumatic brain injury (sTBI) is a leading cause of mortality in children. As clinical prognostication is important in guiding optimal care and decision making, our goal was to create a highly discriminative sTBI outcome prediction model for mortality.

METHODS

Machine learning and advanced analytics were applied to the patient admission variables obtained from a comprehensive pediatric sTBI database. Demographic and clinical data, head CT imaging abnormalities and blood biochemical data from 196 children and adolescents admitted to a tertiary pediatric intensive care unit (PICU) with sTBI were integrated using feature ranking by way of a forest of randomized decision trees, and a model was generated from a reduced number of admission variables with maximal ability to discriminate outcome.

RESULTS

In total, 36 admission variables were analyzed using feature ranking with variable weighting to determine their predictive importance for mortality following sTBI. Reduction analysis utilizing Borata feature selection resulted in a parsimonious six-variable model with a mortality classification accuracy of 82%. The final admission variables that predicted mortality were: partial thromboplastin time (22%); motor Glasgow Coma Scale (21%); serum glucose (16%); fixed pupil(s) (16%); platelet count (13%) and creatinine (12%). Using only these six admission variables, a t-distributed stochastic nearest neighbor embedding algorithm plot demonstrated visual separation of sTBI patients that lived or died, with high mortality predictive ability of this model on the validation dataset (AUC = 0.90) which was confirmed with a conventional area-under-the-curve statistical approach on the total dataset (AUC = 0.91; P < 0.001).

CONCLUSIONS

Machine learning-based modeling identified the most clinically important prognostic factors resulting in a pragmatic, high performing prognostic tool for pediatric sTBI with excellent discriminative ability to predict mortality risk with 82% classification accuracy (AUC = 0.90). After external multicenter validation, our prognostic model might help to guide treatment decisions, aggressiveness of therapy and prepare family members and caregivers for timely end-of-life discussions and decision making.

LEVEL OF EVIDENCE

III; Prognostic.

Occurrence of speech-language disorders in the acute phase following pediatric acquired brain injury: results from the Ghent University Hospital

AIMS

This study investigated the occurrence of speech-language disorders during the acute phase of recovery in children with acquired brain injury (ABI) with an age between 0 and 16 years.

METHODS

A retrospective chart analysis was performed including 228 children (n = 118 boys, n = 110 girls) who consecutively presented with ABI over a 10-year period (2006-2016) at the children's rehabilitation center at Ghent University Hospital. Descriptive statistical analyses were applied.

RESULTS

71.1% (162/228) of the children who were admitted to the rehabilitation center presented with a speech-language disorder. Within this sample (n = 162), results demonstrated the occurrence of acquired disorders in language (48.9%), speech (35.1%), learning (33.3%), swallowing (21.5%), and early communicative functions (17.4%). The proportion of children presenting with disturbances in early communicative functions differed by ABI cause. More than half (10/18, 58.8%) of the children who presented with ABI following inflammatory processes demonstrated disorders in early communicative functions.

CONCLUSIONS

Especially in young children who present with inflammatory processes as the ABI cause, speech-language pathologists (SLPs) must be aware of disorders in early speech-language development. The present findings allow the SLP to appropriately plan research, education, and clinical management.

Cranial molding on neonates in Ghana: mothers' perspective and their knowledge on potential harm to babies' brain

BACKGROUND AND OBJECTIVES

Traditional cranial molding is an ancient practice prevalent in Ghana. In this work, we aimed at assessing mothers'/caregivers' perspective and their knowledge on potential harm of cranial molding on neonates.

METHODS

Two hundred and one (201) nursing mothers with babies aged 1-12 months were sampled in a cross-sectional study using questionnaires. We assessed the mothers'/caregivers' reasons for cranial molding, their perceived benefits of this practice, and their knowledge about the potential harm this practice pose to babies.

RESULTS

Sixty four percent (64%) of mothers confirmed they practice cranial molding on their babies either on their own or through the assistance of a caretaker. However, 72% of all mothers/caregivers did not know this practice has the potential to harm the baby in any way. Mothers'/caregivers' reasons for this practice included the following: to achieve a more "beautiful" head shape, hasten the healing of the fontanelle, and limit head growth. There was a significant association between the mothers'/caregivers' level of education and the practice of cranial molding (p value < 0.05). However, there was no association between head symmetry and cranial molding (p value > 0.05).

CONCLUSIONS AND IMPLICATIONS

Majority of mothers/caregivers were actively engaged in cranial molding on neonates but remain ignorant about the potential harm this practice could have on their babies. Mothers/caregivers therefore need to be educated about the potential harm posed by traditional cranial molding on neonates.

Development of a Mortality Prediction Tool in Pediatric Severe Traumatic Brain Injury

Severe traumatic brain injury (sTBI) is a leading cause of pediatric death, yet outcomes remain difficult to predict. The goal of this study was to develop a predictive mortality tool in pediatric sTBI. We retrospectively analyzed 196 patients with sTBI (pre-sedation Glasgow Coma Scale [GCS] score <8 and head Maximum Abbreviated Injury Scale (MAIS) score >4) admitted to a pediatric intensive care unit (PICU). Overall, 56 patients with sTBI (29%) died during PICU stay. Of the survivors, 88 (63%) were discharged home, and 52 (37%) went to an acute care or rehabilitation facility. Receiver operating characteristic (ROC) curve analyses of admission variables showed that pre-sedation GCS score, Rotterdam computed tomography (CT) score, and partial thromboplastin time (PTT) were fair predictors of PICU mortality (area under the curve [AUC] = 0.79, 0.76, and 0.75, respectively; p < 0.001). Cutoff values best associated with PICU mortality were pre-sedation GCS score <5 (sensitivity = 0.91, specificity = 0.54), Rotterdam CT score >3 (sensitivity = 0.84, specificity = 0.53), and PTT >34.5 sec (sensitivity = 0.69 specificity = 0.67). Combining pre-sedation GCS score, Rotterdam CT score, and PTT in ROC curve analysis yielded an excellent predictor of PICU mortality (AUC = 0.91). In summary, pre-sedation GCS score (<5), Rotterdam CT score (>3), and PTT (>34.5 sec) obtained on hospital admission were fair predictors of PICU mortality, ranked highest to lowest. Combining these three admission variables resulted in an excellent pediatric sTBI mortality prediction tool for further prospective validation.

Identification of adverse events in pediatric severe traumatic brain injury patients to target evidence-based prevention for increased performance improvement and patient safety

INTRODUCTION

Trauma centres are required to continuously measure, evaluate and improve care. Severe traumatic brain injury (sTBI) patients are highly susceptible to adverse events (AE; unintended, potentially harmful events resulting from health care) due to their unstable condition requiring high risk interventions, multiple medications and invasive monitoring. Objectives were to describe: (1) a process for identifying AE in pediatric sTBI patients to identify safety risks, target and implement evidence-based prevention strategies; and (2) a tertiary care PICU's sTBI AE experience.

METHODS

Merging databases, Trauma Registry with Adverse Events Management System, identified AE in patients. Details on the event location, type and severity of harm were combined with patient demographics, injury data, costs and outcomes in a cohort of 193 PICU sTBI patients (2000-15). Descriptive statistics and multivariate logistic regression were undertaken to describe AE, and their association with risk factors and outcomes.

RESULTS

103/193 sTBI patients (53%) suffered at least one AE. 238 AE occurred (1.23 AE/patient), with 30% of patients having 2+ AE. Most resulted in no harm (54%) with decubitus ulcers (15%) the most common AE. AE patients were more likely to be monitored for elevated ICP (p<0.001), with fewer ventilator-free days (p=0.015), longer LOS for PICU (11 vs. 3.5 days; p<0.001) and in-hospital (31 vs. 11 days; p<0.001) with higher median costs ($121,234 vs. $53,341; p=0.031). AE patients required a higher level of care on discharge (p=0.035).

CONCLUSIONS

Merging databases is an effective practice to identify AE and safety risks in trauma populations. Utilizing this method, a PICU AE rate of 1.23 events per patient was found with TBI severity the most important factor to increase the odds of AE. AE represent performance improvement events, opportunities to optimize care, decrease costs, as well as improve outcomes, to ultimately improve patient safety in this vulnerable population.

The Effects of Hesperidin on Neuronal Apoptosis and Cognitive Impairment in the Sevoflurane Anesthetized Rat are Mediated Through the PI3/Akt/PTEN and Nuclear Factor-κB (NF-κB) Signaling Pathways

Background

Hesperidin (HPD) is a bioflavonoid found in citrus fruits. This study aimed to investigate the effects of HPD on cerebral morphology and cognitive behavior in sevoflurane anesthetized neonatal rats and the molecular mechanisms involved.

Material/Methods

Sixty neonatal Sprague–Dawley rats were divided into five groups, including the untreated control group, and the sevoflurane anesthesia groups untreated and treated with 25 mg/kg/day of HPD (HPD25), 50 mg/kg/day of HPD (HPD50), and 100 mg/kg/day of HPD (HPD100). The rat model was created by the administration of sevoflurane on the sixth postnatal day (P6) and for a further three days. Neonatal rats pre-treated with HPD for 19 days were given sevoflurane 30 minutes beforehand (P3 to P21). Rat hippocampal tissue specimens were investigated using the TUNEL assay for apoptosis. Hippocampal tissue homogenates underwent Western blot for the quantification of markers of neuroinflammation and oxidative stress. The neonatal rats were also investigated for behavior, learning, and memory.

Results

HPD significantly reduced sevoflurane-induced neuronal apoptosis and protein expression of cleaved caspase-3, BAD, BAX, NF-κB, TNF-α, IL-6, and IL-1β (p<0.05). HPD significantly increased the expression of Bcl-xL and Bcl-2 (p<0.05), and activated the PI3/Akt pathway. Learning and memory were significantly improved following HPD treatment (p<0.05). HPD treatment modulated the PI3/Akt/PTEN and NF-κB signaling pathways, and reduced oxidative stress (p<0.05).

Conclusions

In the sevoflurane anesthetized neonatal rat model, treatment with HPD reduced neuronal degeneration, hippocampal inflammation, and improvised memory, learning, and cognitive responses by modulating the PI3/Akt/PTEN and NF-κB signaling pathways.

Traumatic brain injury: classification, models, and markers

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality worldwide. Due to its high incidence rate and often long-term sequelae, TBI contributes significantly to increasing costs of health care expenditures annually. Unfortunately, advances in the field have been stifled by patient and injury heterogeneity that pose a major challenge in TBI prevention, diagnosis, and treatment. In this review, we briefly discuss the causes of TBI, followed by its prevalence, classification, and pathophysiology. The current imaging detection methods and animal models used to study brain injury are examined. We discuss the potential use of molecular markers in detecting and monitoring the progression of TBI, with particular emphasis on microRNAs as a novel class of molecular modulators of injury and its repair in the neural tissue.

Analgosedation in paediatric severe traumatic brain injury (TBI): practice, pitfalls and possibilities

Analgosedation is a fundamental part of traumatic brain injury (TBI) treatment guidelines, encompassing both first and second tier supportive strategies. Worldwide analgosedation practices continue to be heterogeneous due to the low level of evidence in treatment guidelines (level III) and the choice of analgosedative drugs is made by the treating clinician. Current practice is thus empirical and may result in unfavourable (often hemodynamic) side effects. This article presents an overview of current analgosedation practices in the paediatric intensive care unit (PICU) and addresses pitfalls both in the short and long term. We discuss innovative (pre-)clinical research that can provide the framework for initiatives to improve our pharmacological understanding of analgesic and sedative drugs used in paediatric severe TBI and ultimately facilitate steps towards evidence-based and precision pharmacotherapy in this vulnerable patient group.

S100B and Neuron-Specific Enolase as mortality predictors in patients with severe traumatic brain injury

OBJECTIVE

To determine temporal profile and prognostic ability of S100B protein and neuron-specific enolase (NSE) for prediction of short/long-term mortality in patients suffering from severe traumatic brain injury (sTBI).

METHODS

Ninety-nine patients with sTBI were included in the study. Blood samples were drawn on admission and on subsequent 24, 48, 72, and 96 h.

RESULTS

15.2% of patients died in NeuroCritical Care Unit, and 19.2% died within 6 months of the accident. S100B concentrations were significantly higher in patients who died compared to survivors. NSE levels were different between groups just at 48 h. In the survival group, S100B levels decreased from 1st to 5th sample (p < 0.001); NSE just from 1st to 3rd (p < 0.001) and then stabilized. Values of S100B and NSE in non-survival patients did not significantly vary over the four days post sTBI. ROC-analysis showed that all S100B samples were useful tools for predicting mortality, the best the 72 h sample (AUC 0.848 for discharge mortality, 0.855 for six-month mortality). NSE ROC-analysis indicated that just the 48-h sample predicted mortality (AUC 0.733 for discharge mortality, 0.720 for six-month mortality).

CONCLUSION

S100B protein showed higher prognostic capacity than NSE to predict short/long-term mortality in sTBI patients.

Blood-brain barrier dysfunction following traumatic brain injury

Traumatic brain injury is a serious cause of morbidity and mortality worldwide. After traumatic brain injury, the blood-brain barrier, the protective barrier between the brain and the intravascular compartment, becomes dysfunctional, leading to leakage of proteins, fluid, and transmigration of immune cells. As this leakage has profound clinical implications, including edema formation, elevated intracranial pressure and decreased perfusion pressure, much interest has been paid to better understanding the mechanisms responsible for these events. Various molecular pathways and numerous mediators have been found to be involved in the intricate process of regulating blood-brain barrier permeability following traumatic brain injury. This review provides an update to the existing knowledge about the various pathophysiological pathways and advancements in the field of blood-brain barrier dysfunction and hyperpermeability following traumatic brain injury, including the role of various tight junction proteins involved in blood-brain barrier integrity and regulation. We also address pitfalls of existing systems and propose strategies to improve the various debilitating functional deficits caused by this progressive epidemic.

A New Rabbit Model of Pediatric Traumatic Brain Injury

Traumatic brain injury (TBI) is a common cause of disability in childhood, resulting in numerous physical, behavioral, and cognitive sequelae, which can influence development through the lifespan. The mechanisms by which TBI influences normal development and maturation remain largely unknown. Pediatric rodent models of TBI often do not demonstrate the spectrum of motor and cognitive deficits seen in patients. To address this problem, we developed a New Zealand white rabbit model of pediatric TBI that better mimics the neurological injury seen after TBI in children. On postnatal Day 5-7 (P5-7), rabbits were injured by a controlled cortical impact (6-mm impactor tip; 5.5 m/sec, 2-mm depth, 50-msec duration). Rabbits from the same litter served as naïve (no injury) and sham (craniotomy alone) controls. Functional abilities and activity levels were measured 1 and 5 d after injury. Maturation level was monitored daily. We performed cognitive tests during P14-24 and sacrificed the animals at 1, 3, 7, and 21 d after injury to evaluate lesion volume and microglia. TBI kits exhibited delayed achievement of normal developmental milestones. They also demonstrated significant cognitive deficits, with lower percentage of correct alternation rate in the T-maze (n=9-15/group; p<0.001) and less discrimination between novel and old objects (p<0.001). Lesion volume increased from 16% at Day 3 to 30% at Day 7 after injury, indicating ongoing secondary injury. Activated microglia were noted at the injury site and also in white matter regions of the ipsilateral and contralateral hemispheres. The neurologic and histologic changes in this model are comparable to those reported clinically. Thus, this rabbit model provides a novel platform for evaluating neuroprotective therapies in pediatric TBI.

Subarachnoid hemorrhage prevalence and its association with short-term outcome in pediatric severe traumatic brain injury

BACKGROUND

Subarachnoid hemorrhage (SAH) is an independent prognostic indicator of outcome in adult severe traumatic brain injury (sTBI). There is a paucity of investigations on SAH in pediatric sTBI. The goal of this study was to determine in pediatric sTBI patients SAH prevalence, associated factors, and its relationship to short-term outcome.

METHODS

We retrospectively analyzed 171 sTBI patients (pre-sedation GCS ≤8 and head MAIS ≥4) who underwent CT head imaging within the first 24 h of hospital admission. Data were analyzed with both univariate and multivariate techniques.

RESULTS

SAH was found in 42 % of sTBI patients (n = 71/171), and it was more frequently associated with skull fractures, cerebral edema, diffuse axonal injury, contusion, and intraventricular hemorrhage (p < 0.05). Patients with SAH had higher Injury Severity Scores (p = 0.032) and a greater frequency of fixed pupil(s) on admission (p = 0.001). There were no significant differences in etiologies between sTBI patients with and without SAH. Worse disposition occurred in sTBI patients with SAH, including increased mortality (p = 0.009), increased episodes of central diabetes insipidus (p = 0.002), greater infection rates (p = 0.002), and fewer ventilator-free days (p = 0.001). In sTBI survivors, SAH was associated with increased lengths of stay (p < 0.001) and a higher level of care required on discharge (p = 0.004). Despite evidence that SAH is linked to poorer outcomes on univariate analyses, multivariate analysis failed to demonstrate an independent association between SAH and mortality (p = 0.969).

CONCLUSION

SAH was present in almost half of pediatric sTBI patients, and it was indicative of TBI severity and a higher level of care on discharge. SAH in pediatric patients was not independently associated with increased risk of mortality.

Brain injury biomarkers as outcome predictors in pediatric severe traumatic brain injury

BACKGROUND

To systematically review the literature on brain injury biomarkers, defined as any injury biomarker detected in cerebrospinal fluid (CSF) or blood injury biomarkers primarily expressed in the brain parenchyma, to determine outcome prediction in pediatric severe traumatic brain injury (sTBI).

METHODS

A search of MEDLINE(®), EMBASE(®), PsycINFO(®), Pubmed(®), and the Cochrane Database, as well as grey literature sources, personal contacts, hand searches, and reference lists. The search terms used were traumatic brain injury, biomarkers, prognosis, and children. No language, publication type, or publication date restrictions were imposed. All articles were critically reviewed by two clinicians independently.

RESULTS

A total of 7,150 articles were identified initially with 16 studies identified for review. Eighteen different biomarkers were examined; 11 in CSF and 7 in blood. Outcomes assessed included either in-hospital mortality or functional state (hospital discharge, 3-months or 6-months; Glasgow Outcome Scale or Pediatric Cerebral Performance Category). Significant correlations were established between sTBI outcomes and various biomarkers in CSF (IL-6, IL-8, IL-1β, S100β, NGF, NSE, DCX, ET-1, HMGB-1, cytochrome C) and blood (GFAP, NF-H, UCH-L1, SBDP-145, leptin). Mixed results were obtained for blood S100β. Outcome did not correlate with several biomarkers in either CSF (BDNF, GDNF, α-Syn) or blood (NSE, MBP). The Class of Evidence was considered II in 1 study and III in the remaining 15 studies.

CONCLUSIONS

Based on the status of current sTBI biomarker research, we recommend that future research should be directed at both novel biomarker discovery and validation of biomarker panels in large, well-designed longitudinal studies.

Pre-administration of curcumin prevents neonatal sevoflurane exposure-induced neurobehavioral abnormalities in mice

Sevoflurane, a commonly used inhaled anesthetic, can induce neuronal apoptosis in the developing rodent brain and correlate with functional neurological impairment later in life. However, the mechanisms underlying these deleterious effects of sevoflurane remain unclear and no effective treatment is currently available. Herein, the authors investigated whether curcumin can prevent the sevoflurane anesthesia-induced cognitive impairment in mice. Six-day-old C57BL/6 mice were exposed to 3% sevoflurane 2h daily for 3 consecutive days and were treated with curcumin at the dose of 20 mg/kg or vehicle 30 min before the sevoflurane anesthesia from postnatal days 6 (P6) to P8. Cognitive functions were evaluated by open field, Morris water maze, and fear conditioning tests on P61, P63-69, and P77-78, respectively. In another separate experiment, mice were killed on day P8 or P78, and the brain tissues were harvested and then subjected to biochemistry studies. Our results showed that repeated neonatal sevoflurane exposure led to significant cognitive impairment later in life, which was associated with increased neuronal apoptosis, neuroinflammation, oxidative nitrosative stress, and decreased memory related proteins. By contrast, pre-administration of curcumin ameliorated early neuronal apoptosis, neuroinflammation, oxidative nitrosative stress, memory related proteins, and later cognitive dysfunction. In conclusion, our data suggested that curcumin pre-administration can prevent the sevoflurane exposure-induced cognitive impairment later in life, which may be partly attributed to its ability to attenuate the neural apoptosis, inflammation, and oxidative nitrosative stress in mouse brain.

Traumatic injury elicits JNK-mediated human astrocyte retraction in vitro

Brain injury causes dysfunction of the blood-brain barrier (BBB). The BBB is comprised of perivascular astrocytes whose end-feet ensheath brain microvascular endothelial cells. We investigated trauma-induced morphological changes of human astrocytes (HA) and human cerebral microvascular endothelial cells (hCMEC/D3) in vitro, including the potential role of mitogen-activated protein kinase (MAPK) signal-transduction pathways. HA or hCMEC/D3 were grown on flexible culture membranes and subjected to single traumatic injury normalized to 20%, 30% or 55% membrane deformation. Cells were assayed for morphological changes (i.e. retraction) and MAPK phosphorylation and/or expression (c-Jun NH2-terminal kinase (JNK)1/2, extracellular signal-regulated kinase (ERK)1/2, and p38). HA retraction was rapidly elicited with a single traumatic injury (55% membrane deformation; p<0.01). Morphological recovery of HA was observed within 2h (p<0.05). Traumatic injuries increased phospho-JNK1/2 (p<0.05) in HA, indicating MAPK activation. Pre-treatment of HA with structurally distinct JNK inhibitors (25μM), either SP600125 or SU3327, reduced JNK phosphorylation (p<0.05) and trauma-induced HA retraction (P<0.05). In contrast to HA, traumatic injury failed to induce either morphological changes or MAPK activation in hCMEC/D3. In summary, traumatic injury induces JNK-mediated HA retraction in vitro, while sparing morphological changes in cerebral microvascular endothelial cells. Astrocyte retraction from microvascular endothelial cells in vivo may occur after brain trauma, resulting in cellular uncoupling and BBB dysfunction. JNK may represent a potential therapeutic target for traumatic brain injuries.

An epidemiologic profile of pediatric concussions: identifying urban and rural differences

BACKGROUND

The objective of this study was to describe the epidemiology of concussions presenting to the emergency department (ED).

METHODS

A retrospective cohort of concussions for pediatric (age < 18 years) patients treated in the ED of a regional pediatric Level 1 trauma center from 2006 to 2011 was examined. Descriptive and geographic analyses were completed, with comparisons by age groups and residence (urban/rural).

RESULTS

There were a total of 2,112 treated pediatric concussions. Two thirds of the concussions occurred in males (67%), with a median age of 13 years (interquartile range [IQR], 6). Nearly half of the pediatric concussions were sports related (48%); 36% of these concussions were from hockey. Significant differences were found in the distribution of the mechanism of injury across age groups (p < 0.001). Falls were most prevalent among young children, and sports concussions, for children 10 years and older. Two fifths of concussions occurred during winter months. Discharge disposition significantly differed by age (p < 0.001), with home discharge increasing with age up to 14 years. There were a total of 387 rural (19%) and 1,687 urban (81%) concussed patients, for a mean ED concussion visit rate of 2.2 per 1,000 and 3.5 per 1,000, respectively. Rural patients were older (14 [IQR, 6] vs. 13 [IQR, 6], p = 0.019] and sustained 2.5 times more concussions from a motor vehicle crash compared with urban youth patients (p < 0.001).

CONCLUSION

Males in early adolescence are at highest risk for concussion, particularly from sport-related activities. Urban and rural children have differences in their etiology and severity of concussions. Concussions are predictable, and their prevention should be targeted based on epidemiologic and environmental data.

LEVEL OF EVIDENCE

Epidemiologic, study, level III.

Age, plasticity, and homeostasis in childhood brain disorders

It has been widely accepted that the younger the age and/or immaturity of the organism, the greater the brain plasticity, the young age plasticity privilege. This paper examines the relation of a young age to plasticity, reviewing human pediatric brain disorders, as well as selected animal models, human developmental and adult brain disorder studies. As well, we review developmental and childhood acquired disorders that involve a failure of regulatory homeostasis. Our core arguments are as follows: